Acute appendicitis
- Overview
- Theory
- Diagnosis
- Management
- Follow up
- Resources
Treatment algorithm
Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer
Look out for this icon: for treatment options that are affected, or added, as a result of your patient's comorbidities.
uncomplicated appendicitis: adults
supportive treatment
Keep the patient nil by mouth if surgery is being considered.
Run intravenous maintenance fluids for any patient who is being kept nil by mouth.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Involve obstetric support for any pregnant woman with appendicitis as management requires a multidisciplinary approach.[84]Weston P, Moroz P. Appendicitis in pregnancy: how to manage and whether to deliver. Obstet Gynecol. 2015 Apr;17(2):105-10.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
appendicectomy
Treatment recommended for ALL patients in selected patient group
Refer any patient with suspected or confirmed appendicitis within 24 hours.
Appendicectomy is the standard treatment for uncomplicated appendicitis.[13]Gorter RR, Eker HH, Gorter-Stam MA, et al. Diagnosis and management of acute appendicitis: EAES consensus development conference 2015. Surg Endosc. 2016 Nov;30(11):4668-90. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5082605 http://www.ncbi.nlm.nih.gov/pubmed/27660247?tool=bestpractice.com
Laparoscopic appendicectomy is preferred over open surgery for most adults (including pregnant women) provided an appropriately skilled surgeon is available.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com [105]Liew AN, Lim KY, Quach D, et al. Laparoscopic versus open appendicectomy in pregnancy: experience from a single institution and meta-analysis. ANZ J Surg. 2022 May;92(5):1071-8. http://www.ncbi.nlm.nih.gov/pubmed/35373462?tool=bestpractice.com [106]Zeng Q, Aierken A, Gu SS, et al. Laparoscopic versus open appendectomy for appendicitis in pregnancy: systematic review and meta-analysis. Surg Laparosc Endosc Percutan Tech. 2021 May 3;31(5):637-44. http://www.ncbi.nlm.nih.gov/pubmed/33935257?tool=bestpractice.com [110]Zhang G, Wu B. Meta-analysis of the clinical efficacy of laparoscopic appendectomy in the treatment of acute appendicitis. World J Emerg Surg. 2022 May 26;17(1):26. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9137214 http://www.ncbi.nlm.nih.gov/pubmed/35619101?tool=bestpractice.com
Ensure appendicectomy is not delayed unnecessarily in order to minimise patient discomfort. However, evidence suggests that delaying surgery by up to 24 hours does not increase the risk of perforation.[85]United Kingdom National Surgical Research Collaborative; Bhangu A. Safety of short, in-hospital delays before surgery for acute appendicitis: multicentre cohort study, systematic review, and meta-analysis. Ann Surg. 2014 May;259(5):894-903. http://www.ncbi.nlm.nih.gov/pubmed/24509193?tool=bestpractice.com
Minimise surgical delay for patients >65 years of age and those with significant comorbidities as these patients may be at increased risk of perforation.[122]Busch M, Gutzwiller FS, Aellig S, et al. In-hospital delay increases the risk of perforation in adults with appendicitis. World J Surg. 2011 Jul;35(7):1626-33. http://www.ncbi.nlm.nih.gov/pubmed/21562871?tool=bestpractice.com
Give all patients prophylactic antibiotics before surgery to reduce the risk of postoperative complications.[86]Andersen BR, Kallehave FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendicectomy. Cochrane Database Syst Rev. 2005 Jul 20;(3):CD001439. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001439.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/16034862?tool=bestpractice.com Check local protocols.
Patients with uncomplicated appendicitis require a single preoperative dose only.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com [86]Andersen BR, Kallehave FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendicectomy. Cochrane Database Syst Rev. 2005 Jul 20;(3):CD001439. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001439.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/16034862?tool=bestpractice.com
Do not give postoperative antibiotics in adults with uncomplicated acute appendicitis, because there is no evidence they decrease the rate of surgical infection.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Do not use a conservative approach if an appendicolith is present, because non-operative management carries a significant failure rate.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com [2]Moris D, Paulson EK, Pappas TN. Diagnosis and management of acute appendicitis in adults: a review. JAMA. 2021 Dec 14;326(22):2299-311. http://www.ncbi.nlm.nih.gov/pubmed/34905026?tool=bestpractice.com
supportive treatment
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Involve obstetric support for any pregnant woman with appendicitis as management requires a multidisciplinary approach.[84]Weston P, Moroz P. Appendicitis in pregnancy: how to manage and whether to deliver. Obstet Gynecol. 2015 Apr;17(2):105-10.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
antibiotics
Treatment recommended for ALL patients in selected patient group
Give conservative management with antibiotics for selected patients, including those who have uncomplicated appendicitis (suspected or confirmed on computed tomographic scan), and do not wish to have, or are unfit for, surgery; ensure the patient is aware of the risk of recurrence of appendicitis.[13]Gorter RR, Eker HH, Gorter-Stam MA, et al. Diagnosis and management of acute appendicitis: EAES consensus development conference 2015. Surg Endosc. 2016 Nov;30(11):4668-90. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5082605 http://www.ncbi.nlm.nih.gov/pubmed/27660247?tool=bestpractice.com [87]Salminen P, Paajanen H, Rautio T, et al. Antibiotic therapy vs appendectomy for treatment of uncomplicated acute appendicitis: the APPAC randomized clinical trial. JAMA. 2015 Jun 16;313(23):2340-8. http://www.ncbi.nlm.nih.gov/pubmed/26080338?tool=bestpractice.com [90]de Almeida Leite RM, Seo DJ, Gomez-Eslava B, et al. Nonoperative vs operative management of uncomplicated acute appendicitis: a systematic review and meta-analysis. JAMA Surg. 2022 Sep 1;157(9):828-34. https://jamanetwork.com/journals/jamasurgery/fullarticle/2794669 http://www.ncbi.nlm.nih.gov/pubmed/35895073?tool=bestpractice.com
Do not use a conservative approach for pregnant patients.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Do not use a conservative approach if an appendicolith is present, because non-operative management carries a significant failure rate.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com [2]Moris D, Paulson EK, Pappas TN. Diagnosis and management of acute appendicitis in adults: a review. JAMA. 2021 Dec 14;326(22):2299-311. http://www.ncbi.nlm.nih.gov/pubmed/34905026?tool=bestpractice.com
Discuss the risks of conservative management and all other potential treatment options with the patient so that they are able to make an informed decision.[127]Supreme Court (UK). Judgment: Montgomery (appellant) v Lanarkshire Health Board (respondent) (Scotland). March 2015 [internet publication]. https://www.supremecourt.uk/cases/docs/uksc-2013-0136-judgment.pdf
Check local protocols and seek advice from microbiology colleagues when prescribing antibiotics as drug regimens and length of treatment varies. Examples of regimens include ceftriaxone plus metronidazole, cefotaxime plus metronidazole, or amoxicillin/clavulanate.
Primary options
ceftriaxone: 1-2 g intravenously every 24 hours
or
cefotaxime: 1 g intravenously every 8-12 hours, may increase to 8-12 g/day given in 3-4 divided doses in severe infections
-- AND --
metronidazole: 500 mg intravenously every 8 hours
OR
amoxicillin/clavulanate: 1.2 g intravenously every 8 hours
More amoxicillin/clavulanateDose consists of 1 g of amoxicillin plus 0.2 g of clavulanate.
These drug options and doses relate to a patient with no comorbidities.
Primary options
ceftriaxone: 1-2 g intravenously every 24 hours
or
cefotaxime: 1 g intravenously every 8-12 hours, may increase to 8-12 g/day given in 3-4 divided doses in severe infections
-- AND --
metronidazole: 500 mg intravenously every 8 hours
OR
amoxicillin/clavulanate: 1.2 g intravenously every 8 hours
More amoxicillin/clavulanateDose consists of 1 g of amoxicillin plus 0.2 g of clavulanate.
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
ceftriaxone
or
cefotaxime
-- AND --
metronidazole
OR
amoxicillin/clavulanate
uncomplicated appendicitis: children
supportive treatment
Keep the patient nil by mouth if surgery is being considered.
Run intravenous maintenance fluids for any patient who is being kept nil by mouth.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide
For fluid resuscitation in children, see Volume depletion in children.
Refer all children with suspected appendicitis to the paediatric surgery team on call, if available. Where no paediatric surgery team is available, joint care should be managed between paediatrics and surgical teams.
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
appendicectomy
Treatment recommended for ALL patients in selected patient group
Refer for surgery if an appendicolith is present, because the failure rate of non-operative management increases in these patients.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com [2]Moris D, Paulson EK, Pappas TN. Diagnosis and management of acute appendicitis in adults: a review. JAMA. 2021 Dec 14;326(22):2299-311. http://www.ncbi.nlm.nih.gov/pubmed/34905026?tool=bestpractice.com
Laparoscopic appendicectomy is preferred over open surgery provided an appropriately skilled surgeon is available.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Ensure appendicectomy is not delayed for children with uncomplicated acute appendicitis beyond 24 hours.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Give all patients prophylactic antibiotics before surgery to reduce the risk of postoperative complications.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com Check local protocols.
Patients with uncomplicated appendicitis require a single preoperative dose only.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Do not give postoperative antibiotics in children with uncomplicated acute appendicitis, because there is no evidence they decrease the rate of surgical infection.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
supportive treatment
Refer all children with suspected appendicitis to the paediatric surgery team on call, if available. Where no paediatric surgery team is available, joint care should be managed between paediatrics and surgical teams.
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
antibiotics
Treatment recommended for ALL patients in selected patient group
Seek a decision from a specialist paediatric surgeon regarding whether to proceed with non-operative management with antibiotics as an alternative to surgery in children.
Give conservative management with antibiotics for selected patients, including those who have uncomplicated appendicitis (suspected or confirmed on computed tomographic scan) .[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Advise that there is a chance of failure and misdiagnosis of complicated appendicitis with non-operative management.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Check local protocols and seek advice from microbiology colleagues when prescribing antibiotics as drug regimens and length of treatment vary.
Examples of regimens include amoxicillin/clavulanate, or ceftriaxone plus metronidazole.
Primary options
amoxicillin/clavulanate: children <3 months of age: 30 mg/kg intravenously every 12 hours; children ≥3 months of age: 30 mg/kg intravenously every 8 hours, maximum 1200 mg/dose
More amoxicillin/clavulanateDose consists of amoxicillin plus clavulanate.
OR
ceftriaxone: children 1 month to 11 years of age or body weight <50 kg: 50-80 mg/kg intravenously every 24 hours, maximum 4000 mg/day; children ≥12 years of age or body weight ≥50 kg: 1-2 g intravenously every 24 hours
and
metronidazole: children 1 month of age: 15 mg/kg intravenously as a loading dose, followed by 7.5 mg/kg every 8 hours; children ≥2 months of age: 7.5 mg/kg intravenously every 8 hours, maximum 500 mg/dose
These drug options and doses relate to a patient with no comorbidities.
Primary options
amoxicillin/clavulanate: children <3 months of age: 30 mg/kg intravenously every 12 hours; children ≥3 months of age: 30 mg/kg intravenously every 8 hours, maximum 1200 mg/dose
More amoxicillin/clavulanateDose consists of amoxicillin plus clavulanate.
OR
ceftriaxone: children 1 month to 11 years of age or body weight <50 kg: 50-80 mg/kg intravenously every 24 hours, maximum 4000 mg/day; children ≥12 years of age or body weight ≥50 kg: 1-2 g intravenously every 24 hours
and
metronidazole: children 1 month of age: 15 mg/kg intravenously as a loading dose, followed by 7.5 mg/kg every 8 hours; children ≥2 months of age: 7.5 mg/kg intravenously every 8 hours, maximum 500 mg/dose
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
amoxicillin/clavulanate
OR
ceftriaxone
and
metronidazole
supportive treatment
Keep the patient nil by mouth if surgery is being considered.
Run intravenous maintenance fluids for any patient who is being kept nil by mouth.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide
For fluid resuscitation in children, see Volume depletion in children.
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
appendicectomy
Treatment recommended for ALL patients in selected patient group
Refer for surgery if conservative management fails.
Failure of medical management may be indicated by persistent fever, unremitting symptoms, or rising inflammatory markers.
Laparoscopic appendicectomy is preferred over open surgery provided an appropriately skilled surgeon is available.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Ensure appendicectomy, if indicated, is not delayed for children with uncomplicated acute appendicitis beyond 24 hours.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Do not give postoperative antibiotics in children with uncomplicated acute appendicitis, because there is no evidence they decrease the rate of surgical infection.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
complicated appendicitis: adults
supportive treatment
Involve critical care and seek immediate surgical input for any patient with suspected perforated appendicitis and signs of shock or sepsis.
If the patient has signs of shock, give a fluid challenge to correct hypotension and/or tachycardia.[79]National Institute for Health and Care Excellence. Intravenous fluid therapy in adults in hospital. May 2017 [internet publication]. https://www.nice.org.uk/guidance/cg174 See Shock.
Give 250-500 mL of either normal saline (0.9% sodium chloride) or Hartmann’s solution (also known as Ringer’s lactate solution), intravenously over 15 minutes.[79]National Institute for Health and Care Excellence. Intravenous fluid therapy in adults in hospital. May 2017 [internet publication]. https://www.nice.org.uk/guidance/cg174
Refer to local guidelines for the recommended approach at your institution for prompt assessment and management of patients with suspected sepsis, or those at risk.[26]National Institute for Health and Care Excellence. Sepsis: recognition, diagnosis and early management. September 2017 [internet publication]. https://www.nice.org.uk/guidance/ng51 [80]NHS England. Sepsis guidance implementation advice for adults. September 2017 [internet publication]. https://www.england.nhs.uk/wp-content/uploads/2017/09/sepsis-guidance-implementation-advice-for-adults.pdf [81]Royal College of Physicians. National early warning score (NEWS) 2: standardising the assessment of acute-illness severity in the NHS. December 2017 [internet publication]. https://www.rcplondon.ac.uk/projects/outputs/national-early-warning-score-news-2 [83]Bion J, Barton G, Boyle A, et al. Academy of Medical Royal Colleges statement on the initial antimicrobial treatment of sepsis V2.0. Oct 2022 [internet publication]. https://www.aomrc.org.uk/reports-guidance/statement-on-the-initial-antimicrobial-treatment-of-sepsis-v2-0 See Sepsis in adults.
Keep the patient nil by mouth if surgery is being considered.
Run intravenous maintenance fluids for any patient who is being kept nil by mouth.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Involve obstetric support for any pregnant woman with appendicitis as management requires a multidisciplinary approach.[84]Weston P, Moroz P. Appendicitis in pregnancy: how to manage and whether to deliver. Obstet Gynecol. 2015 Apr;17(2):105-10.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
emergency appendicectomy
Treatment recommended for ALL patients in selected patient group
Request an immediate surgical review for any patient with confirmed or suspected complicated appendicitis.
Patients with a perforated appendix will need urgent appendicectomy.
Laparoscopic appendicectomy is performed in the vast majority of patients in the UK and should be considered as the treatment of choice for most patients if the expertise is available.[95]Ventham NT, Dungworth JC, Benzoni C. Transition towards laparoscopic appendicectomy at a UK center over a 7-year period. Surg Laparosc Endosc Percutan Tech. 2015 Feb;25(1):59-63. http://www.ncbi.nlm.nih.gov/pubmed/24732741?tool=bestpractice.com [96]Markar SR, Penna M, Harris A. Laparoscopic approach to appendectomy reduces the incidence of short- and long-term post-operative bowel obstruction: systematic review and pooled analysis. J Gastrointest Surg. 2014 Sep;18(9):1683-92. http://www.ncbi.nlm.nih.gov/pubmed/24950775?tool=bestpractice.com
Give all patients prophylactic antibiotics before surgery to reduce the risk of postoperative complications.[86]Andersen BR, Kallehave FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendicectomy. Cochrane Database Syst Rev. 2005 Jul 20;(3):CD001439. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001439.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/16034862?tool=bestpractice.com Check local protocols.
postoperative antibiotics
Treatment recommended for ALL patients in selected patient group
Continue antibiotics postoperatively if complicated appendicitis is confirmed during surgery.[86]Andersen BR, Kallehave FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendicectomy. Cochrane Database Syst Rev. 2005 Jul 20;(3):CD001439. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001439.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/16034862?tool=bestpractice.com
Check local protocols and seek advice from microbiology colleagues on the choice of antibiotic as this will be guided by local resistance patterns. Examples of regimens include amoxicillin plus metronidazole, piperacillin/tazobactam, or amoxicillin/clavulanate.
Continue antibiotics typically for 3 to 5 days; start with intravenous and then switch to oral administration.
Discontinue antibiotics based on resolving clinical signs (e.g,. fever) and laboratory criteria (e.g., leukocytosis).
Primary options
amoxicillin: 500 mg intravenously every 8 hours, may increase to 1000 mg every 6 hours in severe infections
and
metronidazole: 500 mg intravenously every 8 hours
OR
piperacillin/tazobactam: 4.5 g intravenously every 8 hours, may increase to 4.5 g every 6 hours in severe infections
More piperacillin/tazobactamDose consists of 4 g of piperacillin plus 0.5 g of tazobactam.
OR
amoxicillin/clavulanate: 1.2 g intravenously every 8 hours
More amoxicillin/clavulanateDose consists of 1 g of amoxicillin plus 0.2 g of clavulanate.
These drug options and doses relate to a patient with no comorbidities.
Primary options
amoxicillin: 500 mg intravenously every 8 hours, may increase to 1000 mg every 6 hours in severe infections
and
metronidazole: 500 mg intravenously every 8 hours
OR
piperacillin/tazobactam: 4.5 g intravenously every 8 hours, may increase to 4.5 g every 6 hours in severe infections
More piperacillin/tazobactamDose consists of 4 g of piperacillin plus 0.5 g of tazobactam.
OR
amoxicillin/clavulanate: 1.2 g intravenously every 8 hours
More amoxicillin/clavulanateDose consists of 1 g of amoxicillin plus 0.2 g of clavulanate.
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
amoxicillin
and
metronidazole
OR
piperacillin/tazobactam
OR
amoxicillin/clavulanate
supportive treatment
Keep the patient nil by mouth if surgery is being considered.
Run intravenous maintenance fluids for any patient who is being kept nil by mouth.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Involve obstetric support for any pregnant woman with appendicitis as management requires a multidisciplinary approach.[84]Weston P, Moroz P. Appendicitis in pregnancy: how to manage and whether to deliver. Obstet Gynecol. 2015 Apr;17(2):105-10.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
laparoscopic appendicectomy
Treatment recommended for ALL patients in selected patient group
Laparoscopic appendicectomy is recommended as the first-line treatment for a stable patient who has appendicitis with phlegmon or abscess, provided the expertise is available.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
In experienced hands, laparoscopic surgery is associated with fewer readmissions and fewer additional interventions than conservative treatment, with a comparable hospital stay.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Give all patients prophylactic antibiotics before surgery to reduce the risk of postoperative complications.[86]Andersen BR, Kallehave FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendicectomy. Cochrane Database Syst Rev. 2005 Jul 20;(3):CD001439. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001439.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/16034862?tool=bestpractice.com Check local protocols.
postoperative antibiotics
Treatment recommended for ALL patients in selected patient group
Continue antibiotics postoperatively if complicated appendicitis is confirmed during surgery.[86]Andersen BR, Kallehave FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendicectomy. Cochrane Database Syst Rev. 2005 Jul 20;(3):CD001439. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001439.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/16034862?tool=bestpractice.com
Check local protocols and seek advice from microbiology colleagues on the choice of antibiotic as this will be guided by local resistance patterns. Examples of regimens include amoxicillin plus metronidazole, piperacillin/tazobactam, or amoxicillin/clavulanate.
Continue antibiotics typically for 3 to 5 days; start with intravenous and then switch to oral administration.
Discontinue antibiotics based on resolving clinical signs (e.g,. fever) and laboratory criteria (e.g., leukocytosis).
Primary options
amoxicillin: 500 mg intravenously every 8 hours, may increase to 1000 mg every 6 hours in severe infections
and
metronidazole: 500 mg intravenously every 8 hours
OR
piperacillin/tazobactam: 4.5 g intravenously every 8 hours, may increase to 4.5 g every 6 hours in severe infections
More piperacillin/tazobactamDose consists of 4 g of piperacillin plus 0.5 g of tazobactam.
OR
amoxicillin/clavulanate: 1.2 g intravenously every 8 hours
More amoxicillin/clavulanateDose consists of 1 g of amoxicillin plus 0.2 g of clavulanate.
These drug options and doses relate to a patient with no comorbidities.
Primary options
amoxicillin: 500 mg intravenously every 8 hours, may increase to 1000 mg every 6 hours in severe infections
and
metronidazole: 500 mg intravenously every 8 hours
OR
piperacillin/tazobactam: 4.5 g intravenously every 8 hours, may increase to 4.5 g every 6 hours in severe infections
More piperacillin/tazobactamDose consists of 4 g of piperacillin plus 0.5 g of tazobactam.
OR
amoxicillin/clavulanate: 1.2 g intravenously every 8 hours
More amoxicillin/clavulanateDose consists of 1 g of amoxicillin plus 0.2 g of clavulanate.
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
amoxicillin
and
metronidazole
OR
piperacillin/tazobactam
OR
amoxicillin/clavulanate
supportive treatment
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Give opioids if these are required.
Involve obstetric support for any pregnant woman with appendicitis as management requires a multidisciplinary approach.[84]Weston P, Moroz P. Appendicitis in pregnancy: how to manage and whether to deliver. Obstet Gynecol. 2015 Apr;17(2):105-10.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <51 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
antibiotics and percutaneous image-guided drainage
Treatment recommended for ALL patients in selected patient group
If laparoscopic expertise is not available, conservative treatment with intravenous antibiotics and percutaneous image-guided drainage is a reasonable alternative for a stable patient with an abscess/phlegmon.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com Check local protocols and seek advice from microbiology colleagues when prescribing antibiotics as drug regimens and length of treatment varies.
Continue antibiotics for up to 6 weeks; consider interval appendicectomy if symptoms persist or recur.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com [13]Gorter RR, Eker HH, Gorter-Stam MA, et al. Diagnosis and management of acute appendicitis: EAES consensus development conference 2015. Surg Endosc. 2016 Nov;30(11):4668-90. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5082605 http://www.ncbi.nlm.nih.gov/pubmed/27660247?tool=bestpractice.com
Examples of regimens include amoxicillin plus metronidazole, piperacillin/tazobactam, or amoxicillin/clavulanate.
Primary options
amoxicillin: 500 mg intravenously every 8 hours, may increase to 1000 mg every 6 hours in severe infections
and
metronidazole: 500 mg intravenously every 8 hours
OR
piperacillin/tazobactam: 4.5 g intravenously every 8 hours, may increase to 4.5 g every 6 hours in severe infections
More piperacillin/tazobactamDose consists of 4 g of piperacillin plus 0.5 g of tazobactam.
OR
amoxicillin/clavulanate: 1.2 g intravenously every 8 hours
More amoxicillin/clavulanateDose consists of 1 g of amoxicillin plus 0.2 g of clavulanate.
These drug options and doses relate to a patient with no comorbidities.
Primary options
amoxicillin: 500 mg intravenously every 8 hours, may increase to 1000 mg every 6 hours in severe infections
and
metronidazole: 500 mg intravenously every 8 hours
OR
piperacillin/tazobactam: 4.5 g intravenously every 8 hours, may increase to 4.5 g every 6 hours in severe infections
More piperacillin/tazobactamDose consists of 4 g of piperacillin plus 0.5 g of tazobactam.
OR
amoxicillin/clavulanate: 1.2 g intravenously every 8 hours
More amoxicillin/clavulanateDose consists of 1 g of amoxicillin plus 0.2 g of clavulanate.
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
amoxicillin
and
metronidazole
OR
piperacillin/tazobactam
OR
amoxicillin/clavulanate
interval appendicectomy
Additional treatment recommended for SOME patients in selected patient group
Interval appendicectomy should be considered if the patient has had conservative management and symptoms persist or recur.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com [13]Gorter RR, Eker HH, Gorter-Stam MA, et al. Diagnosis and management of acute appendicitis: EAES consensus development conference 2015. Surg Endosc. 2016 Nov;30(11):4668-90. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5082605 http://www.ncbi.nlm.nih.gov/pubmed/27660247?tool=bestpractice.com
The patient is usually discharged to continue antibiotics at home and then readmitted for interval appendicectomy if this is needed.
Ensure any patient aged >40 years who has conservative management without interval appendicectomy also has investigations to rule out colon malignancy; these should include colonoscopy and interval full-dose contrast-enhanced CT scan.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
complicated appendicitis: children
supportive treatment
Involve critical care and seek immediate surgical input for any patient with suspected perforated appendicitis and signs of shock or sepsis.
For fluid resuscitation in children, see Volume depletion in children.
Refer to local guidelines for the recommended approach at your institution for prompt assessment and management of patients with suspected sepsis, or those at risk.[26]National Institute for Health and Care Excellence. Sepsis: recognition, diagnosis and early management. September 2017 [internet publication]. https://www.nice.org.uk/guidance/ng51 [80]NHS England. Sepsis guidance implementation advice for adults. September 2017 [internet publication]. https://www.england.nhs.uk/wp-content/uploads/2017/09/sepsis-guidance-implementation-advice-for-adults.pdf [81]Royal College of Physicians. National early warning score (NEWS) 2: standardising the assessment of acute-illness severity in the NHS. December 2017 [internet publication]. https://www.rcplondon.ac.uk/projects/outputs/national-early-warning-score-news-2 [83]Bion J, Barton G, Boyle A, et al. Academy of Medical Royal Colleges statement on the initial antimicrobial treatment of sepsis V2.0. Oct 2022 [internet publication]. https://www.aomrc.org.uk/reports-guidance/statement-on-the-initial-antimicrobial-treatment-of-sepsis-v2-0 See Sepsis in children.
Keep the patient nil by mouth if surgery is being considered.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide
For fluid resuscitation in children, see Volume depletion in children.
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
emergency appendicectomy
Treatment recommended for ALL patients in selected patient group
Request an immediate surgical review for any child with confirmed or suspected complicated appendicitis. Children with a perforated appendix and/or those who are acutely unwell will need urgent (within 8 hours) appendicectomy.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Laparoscopic appendicectomy is preferred over open appendicectomy where laparoscopic equipment and expertise are available.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com [157]Neogi S, Banerjee A, Panda SS, et al. Laparoscopic versus open appendicectomy for complicated appendicitis in children: a systematic review and meta-analysis. J Pediatr Surg. 2022 Mar;57(3):394-405. http://www.ncbi.nlm.nih.gov/pubmed/34332757?tool=bestpractice.com
Give all patients prophylactic antibiotics before surgery to reduce the risk of postoperative complications.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com Follow local protocols.
postoperative antibiotics
Treatment recommended for ALL patients in selected patient group
Give postoperative antibiotics to any child with complicated appendicitis.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Seek advice from microbiology colleagues on the choice of antibiotic as this will be guided by local resistance patterns. Examples of regimens include piperacillin/tazobactam and amoxicillin/clavulanate.
Continue postoperative antibiotics for less than 7 days; start with intravenous and then switch to oral administration after 48 hours.
Discontinue antibiotics based on resolving clinical signs (e.g., fever) and laboratory criteria (e.g., leukocytosis).
Primary options
amoxicillin/clavulanate: children <3 months of age: 30 mg/kg intravenously every 12 hours; children ≥3 months of age: 30 mg/kg intravenously every 8 hours, maximum 1200 mg/dose
More amoxicillin/clavulanateDose consists of amoxicillin plus clavulanate.
OR
piperacillin/tazobactam: children 2-11 years of age: 112.5 mg/kg intravenously every 8 hours, maximum 4500 mg/dose
More piperacillin/tazobactamDose consists of piperacillin plus tazobactam.
These drug options and doses relate to a patient with no comorbidities.
Primary options
amoxicillin/clavulanate: children <3 months of age: 30 mg/kg intravenously every 12 hours; children ≥3 months of age: 30 mg/kg intravenously every 8 hours, maximum 1200 mg/dose
More amoxicillin/clavulanateDose consists of amoxicillin plus clavulanate.
OR
piperacillin/tazobactam: children 2-11 years of age: 112.5 mg/kg intravenously every 8 hours, maximum 4500 mg/dose
More piperacillin/tazobactamDose consists of piperacillin plus tazobactam.
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
amoxicillin/clavulanate
OR
piperacillin/tazobactam
supportive treatment
Keep the patient nil by mouth if surgery is being considered.
Run intravenous maintenance fluids for any patient who is being kept nil by mouth.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide
For fluid resuscitation in children, see Volume depletion in children.
Refer all children with suspected appendicitis to the paediatric surgery team on call, if available. Where no paediatric surgery team is available, joint care should be managed between paediatrics and surgical teams.
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
laparoscopic appendicectomy
Treatment recommended for ALL patients in selected patient group
Laparoscopic appendicectomy is recommended as the first-line treatment for a stable patient who has appendicitis with phlegmon or abscess, provided the expertise is available.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com [138]Ahmed A, Feroz SH, Dominic JL, et al. Is emergency appendicectomy better than elective appendicectomy for the treatment of appendiceal phlegmon?: A Review. Cureus. 2020 Dec 12;12(12):e12045. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7802400 http://www.ncbi.nlm.nih.gov/pubmed/33447475?tool=bestpractice.com
In experienced hands, laparoscopic surgery is associated with fewer readmissions and fewer additional interventions than conservative treatment, with a comparable hospital stay.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Give all patients prophylactic antibiotics before surgery to reduce the risk of postoperative complications.[86]Andersen BR, Kallehave FL, Andersen HK. Antibiotics versus placebo for prevention of postoperative infection after appendicectomy. Cochrane Database Syst Rev. 2005 Jul 20;(3):CD001439. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001439.pub2/full http://www.ncbi.nlm.nih.gov/pubmed/16034862?tool=bestpractice.com Check local protocols.
postoperative antibiotics
Treatment recommended for ALL patients in selected patient group
Give postoperative antibiotics to any child with complicated appendicitis.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Seek advice from microbiology colleagues on the choice of antibiotic as this will be guided by local resistance patterns. Examples of regimens include piperacillin/tazobactam and amoxicillin/clavulanate.
Continue postoperative antibiotics for less than 7 days; start with intravenous and then switch to oral administration after 48 hours.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Discontinue antibiotics based on resolving clinical signs (e.g., fever) and laboratory criteria (e.g., leukocytosis).
Primary options
amoxicillin/clavulanate: children <3 months of age: 30 mg/kg intravenously every 12 hours; children ≥3 months of age: 30 mg/kg intravenously every 8 hours, maximum 1200 mg/dose
More amoxicillin/clavulanateDose consists of amoxicillin plus clavulanate.
OR
piperacillin/tazobactam: children 2-11 years of age: 112.5 mg/kg intravenously every 8 hours, maximum 4500 mg/dose
More piperacillin/tazobactamDose consists of piperacillin plus tazobactam.
These drug options and doses relate to a patient with no comorbidities.
Primary options
amoxicillin/clavulanate: children <3 months of age: 30 mg/kg intravenously every 12 hours; children ≥3 months of age: 30 mg/kg intravenously every 8 hours, maximum 1200 mg/dose
More amoxicillin/clavulanateDose consists of amoxicillin plus clavulanate.
OR
piperacillin/tazobactam: children 2-11 years of age: 112.5 mg/kg intravenously every 8 hours, maximum 4500 mg/dose
More piperacillin/tazobactamDose consists of piperacillin plus tazobactam.
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
amoxicillin/clavulanate
OR
piperacillin/tazobactam
supportive treatment
Refer all children with suspected appendicitis to the paediatric surgery team on call, if available. Where no paediatric surgery team is available, joint care should be managed between paediatrics and surgical teams.
Give adequate analgesia.[27]Association of Surgeons of Great Britain and Ireland; Royal College of Surgeons of England. Commissioning guide: emergency general surgery (acute abdominal pain). April 2014 [internet publication]. https://www.rcseng.ac.uk/library-and-publications/rcs-publications/docs/emergency-general-guide [37]Manterola C, Vial M, Moraga J, et al. Analgesia in patients with acute abdominal pain. Cochrane Database Syst Rev. 2011 Jan 19;(1):CD005660. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD005660.pub3/full http://www.ncbi.nlm.nih.gov/pubmed/21249672?tool=bestpractice.com
Paracetamol may be used, or give an opioid (e.g., morphine) if required.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
These drug options and doses relate to a patient with no comorbidities.
Primary options
paracetamol: <10 kg body weight: 10 mg/kg intravenously every 4-6 hours when required, maximum 30 mg/kg/day; 10-50 kg body weight: 15 mg/kg intravenously every 4-6 hours when required, maximum 60 mg/kg/day; ≥51 kg body weight: 1000 mg intravenously every 4-6 hours when required, maximum 4000 mg/day (3000 mg/day if risk factors for hepatotoxicity)
OR
morphine sulfate: consult specialist for guidance on dose
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
paracetamol
OR
morphine sulfate
antibiotics and percutaneous image-guided drainage
Treatment recommended for ALL patients in selected patient group
If laparoscopic expertise is not available, conservative treatment with intravenous antibiotics and percutaneous image-guided drainage is a reasonable alternative for a stable patient with an abscess/phlegmon.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Meta-analyses in children with phlegmon or abscess have found that non-operative management is associated with lower complication and readmission rates and reduced length of hospital stay.
Check local protocols and seek advice from microbiology colleagues when prescribing antibiotics as drug regimens and length of treatment vary.
Continue antibiotics for up to 6 weeks; consider interval appendicectomy if symptoms persist or recur.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com
Examples of regimens include piperacillin/tazobactam and amoxicillin/clavulanate.
Primary options
amoxicillin/clavulanate: children <3 months of age: 30 mg/kg intravenously every 12 hours; children ≥3 months of age: 30 mg/kg intravenously every 8 hours, maximum 1200 mg/dose
More amoxicillin/clavulanateDose consists of amoxicillin plus clavulanate.
OR
piperacillin/tazobactam: children 2-11 years of age: 112.5 mg/kg intravenously every 8 hours, maximum 4500 mg/dose
More piperacillin/tazobactamDose consists of piperacillin plus tazobactam.
These drug options and doses relate to a patient with no comorbidities.
Primary options
amoxicillin/clavulanate: children <3 months of age: 30 mg/kg intravenously every 12 hours; children ≥3 months of age: 30 mg/kg intravenously every 8 hours, maximum 1200 mg/dose
More amoxicillin/clavulanateDose consists of amoxicillin plus clavulanate.
OR
piperacillin/tazobactam: children 2-11 years of age: 112.5 mg/kg intravenously every 8 hours, maximum 4500 mg/dose
More piperacillin/tazobactamDose consists of piperacillin plus tazobactam.
Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.
Show drug information for a patient with no comorbidities
Primary options
amoxicillin/clavulanate
OR
piperacillin/tazobactam
interval appendicectomy
Additional treatment recommended for SOME patients in selected patient group
Interval appendicectomy should be considered if the patient has had conservative management and symptoms persist or recur.[7]Di Saverio S, Podda M, de Simone B, et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg. 2020 Apr 15;15(1):27. https://wjes.biomedcentral.com/articles/10.1186/s13017-020-00306-3 http://www.ncbi.nlm.nih.gov/pubmed/32295644?tool=bestpractice.com The patient is usually discharged to continue antibiotics at home and then readmitted for interval appendicectomy if this is needed.
Choose a patient group to see our recommendations
Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer
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